aodh/ceilometer/plugin.py
Mehdi Abaakouk 5995bf906c Replace oslo.rpc by oslo.messaging
The patch replaces oslo.rpc by oslo.messaging.

The important changes:
- On the collector, the queue name and the topic are now the same
  (ie: metering, instead of ceilometer.collector.metering for the queue
  and metering for the topic)
- Same for the alarm partitionner the queue is no more prefixed by
  ceilometer.alarm.

Implements switch-to-oslo.messaging

Change-Id: Ia5e4ff1dd1d419c090b8039627234ae7f07e8660
2014-04-14 11:56:56 +02:00

127 lines
4.1 KiB
Python

# -*- encoding: utf-8 -*-
#
# Copyright © 2012 New Dream Network, LLC (DreamHost)
#
# Author: Doug Hellmann <doug.hellmann@dreamhost.com>
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
"""Base class for plugins.
"""
import abc
import collections
import fnmatch
import oslo.messaging
import six
from ceilometer.openstack.common.gettextutils import _ # noqa
from ceilometer.openstack.common import log
LOG = log.getLogger(__name__)
ExchangeTopics = collections.namedtuple('ExchangeTopics',
['exchange', 'topics'])
class PluginBase(object):
"""Base class for all plugins.
"""
@six.add_metaclass(abc.ABCMeta)
class NotificationBase(PluginBase):
"""Base class for plugins that support the notification API."""
@abc.abstractproperty
def event_types(self):
"""Return a sequence of strings defining the event types to be
given to this plugin.
"""
def get_targets(self, conf):
"""Return a sequence of oslo.messaging.Target defining the exchange and
topics to be connected for this plugin.
:param conf: Configuration.
"""
#TODO(sileht): Backwards compatibility, remove in J+1
if hasattr(self, 'get_exchange_topics'):
LOG.warn(_('get_exchange_topics API of NotificationPlugin is'
'deprecated, implements get_targets instead.'))
targets = []
for exchange, topics in self.get_exchange_topics(conf):
targets.extend([oslo.messaging.Target(topic=topic,
exchange=exchange)
for topic in topics])
return targets
@abc.abstractmethod
def process_notification(self, message):
"""Return a sequence of Counter instances for the given message.
:param message: Message to process.
"""
@staticmethod
def _handle_event_type(event_type, event_type_to_handle):
"""Check whether event_type should be handled according to
event_type_to_handle.
"""
return any(map(lambda e: fnmatch.fnmatch(event_type, e),
event_type_to_handle))
def to_samples(self, notification):
"""Return samples produced by *process_notification* for the given
notification, if it's handled by this notification handler.
:param notification: The notification to process.
"""
if self._handle_event_type(notification['event_type'],
self.event_types):
return self.process_notification(notification)
return []
@six.add_metaclass(abc.ABCMeta)
class PollsterBase(PluginBase):
"""Base class for plugins that support the polling API."""
@abc.abstractmethod
def get_samples(self, manager, cache, resources=[]):
"""Return a sequence of Counter instances from polling the resources.
:param manager: The service manager class invoking the plugin.
:param cache: A dictionary to allow pollsters to pass data
between themselves when recomputing it would be
expensive (e.g., asking another service for a
list of objects).
:param resources: A list of the endpoints the pollster will get data
from. It's up to the specific pollster to decide
how to use it.
"""
@six.add_metaclass(abc.ABCMeta)
class DiscoveryBase(object):
@abc.abstractmethod
def discover(self, param=None):
"""Discover resources to monitor.
:param param: an optional parameter to guide the discovery
"""